The cataloger looks at this tag in horror - this is context dependent and temporary! Well, so was East Germany!
Why can't I tag my email?
I can move emails into different folders, but then I have to remember which folder to go to when I want something.
I can save a search as a virtual folder, but it's hard to catch everything without human discretion. An email about rehearsals might not contain the word Hartwell at all, but I still want to see it in my "Hartwell" view/folder/search/category.
If we could tag emails, we could add information that would aid findability later on. I reckon we'll see tagging come to email in some form this year. If not to stand-alone email clients, then to web-based services like Gmail.
In Opera, you can create "views", which is a start: you can place a message in a view without taking it out of your main Inbox. But having to create views first means less flexibility than being able to add tags freely. Plus, it doesn't play well with IMAP, and I need to have access to my email (and tags if I had them) from multiple locations.
What do you think? Would you like the option to tag emails as you read them?